blocks|key|365464|text|您可以在第一个元素上查看check+is_array()，前提是如果一个数组的第一个元素是一个数组，那么其他元素也是。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|365465|entityMap^0|I|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

You could look check <code>is_array()</code> on the first element, under the assumption that if the first element of an array is an array, then the rest of them are too.

blocks|key|3366049|text|此函数将返回整数个数组维数(从here窃取)。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3366050|function+countdim($array)
{
+++if+(is_array(reset($array)))+
+++++$return+=+countdim(reset($array))+%2B+1;
+++else
+++++$return+=+1;

+++return+$return;
}|code-block|syntax|javascript|3366051|entityMap|0|LINK|mutability|MUTABLE|url|http://theserverpages.com/php/manual/en/ref.array.php^0|F|4|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

This function will return int number of array dimensions (stolen from <a href="http://theserverpages.com/php/manual/en/ref.array.php" rel="nofollow noreferrer">here</a>).

<pre><code>function countdim($array)
{
 if (is_array(reset($array))) 
 $return = countdim(reset($array)) + 1;
 else
 $return = 1;

 return $return;
}
</code></pre>

blocks|key|365514|text|简短的回答是，如果‘第二维’可以在任何地方，你不能在没有隐式循环的情况下做到这一点。如果一定要放在第一个项目中，你可以这样做|type|unstyled|depth|inlineStyleRanges|entityRanges|data|365515|is_array($arr[0]);|code-block|syntax|javascript|365516|但是，我能找到的最有效的通用方法是在数组上使用foreach循环，只要找到命中就缩短路径(至少隐式循环比直接的for()更好)：|365517|$+more+multi.php
<?php

$a+=+array(1+=>+'a',2+=>+'b',3+=>+array(1,2,3));
$b+=+array(1+=>+'a',2+=>+'b');
$c+=+array(1+=>+'a',2+=>+'b','foo'+=>+array(1,array(2)));

function+is_multi($a)+{
++++$rv+=+array_filter($a,'is_array');
++++if(count($rv)>0)+return+true;
++++return+false;
}

function+is_multi2($a)+{
++++foreach+($a+as+$v)+{
++++++++if+(is_array($v))+return+true;
++++}
++++return+false;
}

function+is_multi3($a)+{
++++$c+=+count($a);
++++for+($i=0;$i<$c;$i%2B%2B)+{
++++++++if+(is_array($a[$i]))+return+true;
++++}
++++return+false;
}
$iters+=+500000;
$time+=+microtime(true);
for+($i+=+0;+$i+<+$iters;+$i%2B%2B)+{
++++is_multi($a);
++++is_multi($b);
++++is_multi($c);
}
$end+=+microtime(true);
echo+"is_multi++took+".($end-$time)."+seconds+in+$iters+times\n";

$time+=+microtime(true);
for+($i+=+0;+$i+<+$iters;+$i%2B%2B)+{
++++is_multi2($a);
++++is_multi2($b);
++++is_multi2($c);
}
$end+=+microtime(true);
echo+"is_multi2+took+".($end-$time)."+seconds+in+$iters+times\n";
$time+=+microtime(true);
for+($i+=+0;+$i+<+$iters;+$i%2B%2B)+{
++++is_multi3($a);
++++is_multi3($b);
++++is_multi3($c);
}
$end+=+microtime(true);
echo+"is_multi3+took+".($end-$time)."+seconds+in+$iters+times\n";
?>

$+php+multi.php
is_multi++took+7.53565130424+seconds+in+500000+times
is_multi2+took+4.56964588165+seconds+in+500000+times
is_multi3+took+9.01706600189+seconds+in+500000+times|365518|隐式循环，但我们不能一找到匹配就走捷径...|365519|$+more+multi.php
<?php

$a+=+array(1+=>+'a',2+=>+'b',3+=>+array(1,2,3));
$b+=+array(1+=>+'a',2+=>+'b');

function+is_multi($a)+{
++++$rv+=+array_filter($a,'is_array');
++++if(count($rv)>0)+return+true;
++++return+false;
}

var_dump(is_multi($a));
var_dump(is_multi($b));
?>

$+php+multi.php
bool(true)
bool(false)|365520|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

The short answer is no you can't do it without at least looping implicitly if the 'second dimension' could be anywhere. If it has to be in the first item, you'd just do 

<pre><code>is_array($arr[0]);
</code></pre>

But, the most efficient general way I could find is to use a foreach loop on the array, shortcircuiting whenever a hit is found (at least the implicit loop is better than the straight for()):

<pre><code>$ more multi.php
&lt;?php

$a = array(1 =&gt; 'a',2 =&gt; 'b',3 =&gt; array(1,2,3));
$b = array(1 =&gt; 'a',2 =&gt; 'b');
$c = array(1 =&gt; 'a',2 =&gt; 'b','foo' =&gt; array(1,array(2)));

function is_multi($a) {
 $rv = array_filter($a,'is_array');
 if(count($rv)&gt;0) return true;
 return false;
}

function is_multi2($a) {
 foreach ($a as $v) {
 if (is_array($v)) return true;
 }
 return false;
}

function is_multi3($a) {
 $c = count($a);
 for ($i=0;$i&lt;$c;$i++) {
 if (is_array($a[$i])) return true;
 }
 return false;
}
$iters = 500000;
$time = microtime(true);
for ($i = 0; $i &lt; $iters; $i++) {
 is_multi($a);
 is_multi($b);
 is_multi($c);
}
$end = microtime(true);
echo "is_multi took ".($end-$time)." seconds in $iters times\n";

$time = microtime(true);
for ($i = 0; $i &lt; $iters; $i++) {
 is_multi2($a);
 is_multi2($b);
 is_multi2($c);
}
$end = microtime(true);
echo "is_multi2 took ".($end-$time)." seconds in $iters times\n";
$time = microtime(true);
for ($i = 0; $i &lt; $iters; $i++) {
 is_multi3($a);
 is_multi3($b);
 is_multi3($c);
}
$end = microtime(true);
echo "is_multi3 took ".($end-$time)." seconds in $iters times\n";
?&gt;

$ php multi.php
is_multi took 7.53565130424 seconds in 500000 times
is_multi2 took 4.56964588165 seconds in 500000 times
is_multi3 took 9.01706600189 seconds in 500000 times
</code></pre>

Implicit looping, but we can't shortcircuit as soon as a match is found...

<pre><code>$ more multi.php
&lt;?php

$a = array(1 =&gt; 'a',2 =&gt; 'b',3 =&gt; array(1,2,3));
$b = array(1 =&gt; 'a',2 =&gt; 'b');

function is_multi($a) {
 $rv = array_filter($a,'is_array');
 if(count($rv)&gt;0) return true;
 return false;
}

var_dump(is_multi($a));
var_dump(is_multi($b));
?&gt;

$ php multi.php
bool(true)
bool(false)
</code></pre>

blocks|key|362808|text|对于PHP+4.2.0或更高版本：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|362809|function+is_multi($array)+{
++++return+(count($array)+!=+count($array,+1));
}|code-block|syntax|javascript|362810|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

For PHP 4.2.0 or newer:

<pre><code>function is_multi($array) {
 return (count($array) != count($array, 1));
}
</code></pre>

blocks|key|360849|text|使用count()两次；一次在默认模式下，一次在递归模式下。如果值匹配，则数组不是多维数组，因为多维数组具有更高的递归计数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|360850|if+(count($array)+==+count($array,+COUNT_RECURSIVE))+
{
++echo+'array+is+not+multidimensional';
}
else
{
++echo+'array+is+multidimensional';
}|code-block|syntax|javascript|360851|这个选项的第二个值mode是在PHP4.2.0中添加的。从PHP+Docs|offset|length|style|CODE|360852|360853|如果可选模式参数设置为COUNT_RECURSIVE+(或1)，count()将递归计数数组。这对于计算多维数组的所有元素特别有用。count()不检测无限递归。|blockquote|360854|360855|360856|但是，此方法不能检测array(array())。|360857|entityMap|0|LINK|mutability|MUTABLE|url|http://us.php.net/count^0|0|0|9|4|T|8|0|0|0|0|0|0|A|E|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|14|8|@$I|15|J|16|K|L]]|9|@$I|17|J|18|1|19]]|A|$]]|$1|M|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]|$1|N|3|O|5|P|7|1B|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|R|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1E|8|@$I|1F|J|1G|K|L]]|9|@]|A|$]]|$1|U|3|-4|5|6|7|1H|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11]]]]

Use count() twice; one time in default mode and one time in recursive mode. If the values match, the array is not multidimensional, as a multidimensional array would have a higher recursive count.

<pre><code>if (count($array) == count($array, COUNT_RECURSIVE)) 
{
 echo 'array is not multidimensional';
}
else
{
 echo 'array is multidimensional';
}
</code></pre>

This option second value <code>mode</code> was added in PHP 4.2.0. From the <a href="http://us.php.net/count" rel="noreferrer">PHP Docs</a>:

<blockquote>
 If the optional mode parameter is set to COUNT_RECURSIVE (or 1), count() will recursively count the array. This is particularly useful for counting all the elements of a multidimensional array. count() does not detect infinite recursion.
</blockquote>

However this method does not detect <code>array(array())</code>.

blocks|key|3153267|text|is_array($arr[key($arr)]);+|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3153268|没有循环，简单明了。|unstyled|3153269|也适用于关联数组，不仅仅是数字数组，它不能包含0+(就像在前面的例子中一样，如果数组没有0，就会抛出一个警告。)|3153270|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>is_array($arr[key($arr)]); 
</code></pre>

No loops, plain and simple.

Works also with associate arrays not only numeric arrays, which could not contain 0 ( like in the previous example would throw you a warning if the array doesn't have a 0. )

blocks|key|365562|text|function+isMultiArray(array+$value)
{
++++return+is_array(reset($value));
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|365563|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>function isMultiArray(array $value)
{
 return is_array(reset($value));
}
</code></pre>

blocks|key|360937|text|我想你会发现这个函数是最简单、最有效、最快的方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|360938|function+isMultiArray($a){
++++foreach($a+as+$v)+if(is_array($v))+return+TRUE;
++++return+FALSE;
}|code-block|syntax|javascript|360939|您可以像这样测试它：|360940|$a+=+array(1+=>+'a',2+=>+'b',3+=>+array(1,2,3));
$b+=+array(1+=>+'a',2+=>+'b');

echo+isMultiArray($a)+?+'is+multi':'is+not+multi';
echo+'<br+/>';
echo+isMultiArray($b)+?+'is+multi':'is+not+multi';|360941|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I think you will find that this function is the simplest, most efficient, and fastest way.

<pre><code>function isMultiArray($a){
 foreach($a as $v) if(is_array($v)) return TRUE;
 return FALSE;
}
</code></pre>

You can test it like this:

<pre><code>$a = array(1 =&gt; 'a',2 =&gt; 'b',3 =&gt; array(1,2,3));
$b = array(1 =&gt; 'a',2 =&gt; 'b');

echo isMultiArray($a) ? 'is multi':'is not multi';
echo '&lt;br /&gt;';
echo isMultiArray($b) ? 'is multi':'is not multi';
</code></pre>

blocks|key|3153492|text|您还可以像这样执行简单的检查：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3153493|$array+=+array('yo'=>'dream',+'mydear'=>+array('anotherYo'=>'dream'));
$array1+=+array('yo'=>'dream',+'mydear'=>+'not_array');

function+is_multi_dimensional($array){
++++$flag+=+0;
++++while(list($k,$value)=each($array)){
++++++++if(is_array($value))
++++++++++++$flag+=+1;
++++}
++++return+$flag;
}
echo+is_multi_dimensional($array);+//+returns+1
echo+is_multi_dimensional($array1);+//+returns+0|code-block|syntax|javascript|3153494|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can also do a simple check like this:

<pre><code>$array = array('yo'=&gt;'dream', 'mydear'=&gt; array('anotherYo'=&gt;'dream'));
$array1 = array('yo'=&gt;'dream', 'mydear'=&gt; 'not_array');

function is_multi_dimensional($array){
 $flag = 0;
 while(list($k,$value)=each($array)){
 if(is_array($value))
 $flag = 1;
 }
 return $flag;
}
echo is_multi_dimensional($array); // returns 1
echo is_multi_dimensional($array1); // returns 0
</code></pre>

blocks|key|3153523|text|都是很棒的答案。下面是我经常使用的三行代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3153524|function+isMultiArray($a){
++++foreach($a+as+$v)+if(is_array($v))+return+TRUE;
++++return+FALSE;
}|code-block|syntax|javascript|3153525|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

All great answers... here's my three lines that I'm always using

<pre><code>function isMultiArray($a){
 foreach($a as $v) if(is_array($v)) return TRUE;
 return FALSE;
}
</code></pre>

blocks|key|360959|text|if($array[0]){
//enter+your+code+
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|360960|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>if($array[0]){
//enter your code 
}
</code></pre>

blocks|key|362355|text|您可以简单地执行以下命令：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|362356|if+(count($myarray)+!==+count($myarray,+COUNT_RECURSIVE))+return+true;
else+return+false;|code-block|syntax|javascript|362357|如果可选模式参数设置为COUNT_RECURSIVE+(或1)，count()将递归地对数组进行计数。这对于计算多维数组的所有元素特别有用。|offset|length|style|CODE|362358|如果它是相同的，意味着任何地方都没有子层。简单而快速！|362359|entityMap^0|0|0|B|F|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

You can simply execute this: 

<pre><code>if (count($myarray) !== count($myarray, COUNT_RECURSIVE)) return true;
else return false;
</code></pre>

If the optional mode parameter is set to <code>COUNT_RECURSIVE</code> (or 1), count() will recursively count the array. This is particularly useful for counting all the elements of a multidimensional array.

If it's the same, means there are no sublevels anywhere. Easy and fast!

blocks|key|365678|text|我认为这是一个优雅的(道具给另一个用户，我不知道他的用户名)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|365679|static+public+function+isMulti($array)
{
++++$result+=+array_unique(array_map("gettype",$array));

++++return+count($result)+==+1+&&+array_shift($result)+==+"array";
}|code-block|syntax|javascript|365680|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I think this one is classy (props to another user I don't know his username):

<pre><code>static public function isMulti($array)
{
 $result = array_unique(array_map("gettype",$array));

 return count($result) == 1 &amp;&amp; array_shift($result) == "array";
}
</code></pre>

blocks|key|362928|text|if+(+array_key_exists(0,$array)+)+{

//+multidimensional+array

}++else+{

//+not+a+multidimensional+array

}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|362929|*仅适用于具有数值索引的数组|unstyled|362930|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>if ( array_key_exists(0,$array) ) {

// multidimensional array

} else {

// not a multidimensional array

}
</code></pre>


*only to those arrays with numeric index

blocks|key|362948|text|以上所有方法都太复杂，无法快速展开。如果数组是平面的，测试第一个元素应该返回一个原语，例如int，string+e.t.c。如果它是多维的，它应该返回一个数组。通过扩展，您可以快速和整洁地使用这一个线性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|362949|echo+is_array(array_shift($myArray));|code-block|syntax|javascript|362950|如果返回true，则数组是多维的。否则它就是扁平的。需要注意的是，数组具有不同维度的情况非常少见，例如，如果您从模型生成数据，那么它将始终具有可被循环遍历的相同类型的多维或平面结构。|362951|📷|atomic|offset|length|362952|如果不是，那么你已经手工定制了它，这意味着你知道所有东西将在哪里，它不需要编写循环算法就可以工作|362953|362954|​|362955|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/9cc4832ce16604175274c3583dd7921a.png|imageAlt|1|https://ask.qcloudimg.com/http-save/yehe-900000/5b2ada30fcc8f7dda255f0c0cc860caf.png^0|0|0|0|0|1|0|0|0|0|1|1|0|0^^$0|@$1|2|3|4|5|6|7|13|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|15|8|@]|9|@]|A|$]]|$1|I|3|J|5|K|7|16|8|@]|9|@$L|17|M|18|1|19]]|A|$]]|$1|N|3|O|5|6|7|1A|8|@]|9|@]|A|$]]|$1|P|3|J|5|K|7|1B|8|@]|9|@$L|1C|M|1D|1|1E]]|A|$]]|$1|Q|3|R|5|6|7|1F|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|1G|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z|10|-4]]|11|$5|V|W|X|A|$Y|12|10|-4]]]]

All the above methods are too complex for quick rolling out. If an array is flat, testing the first element should return a primitive e.g int, string e.t.c. If it is multidimensional, it should return an array. By extension, you can use this one liner fast and neat.

<pre><code>echo is_array(array_shift($myArray));
</code></pre>

if this returns true, the array is multidimensional. Else it is flat. Just to note, it is very rare for arrays to have different dimensions e.g. if you are generating data from a model, it will always have the same type of multidimensional or flat structure that can be traversed by loops. 
<a href="https://i.stack.imgur.com/nsUWA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nsUWA.png" alt="machine made loops"></a>
If it isn't, then you have custom built it by hand, which means you know where everything will be and it just works without needing to write a looping algorithm
<a href="https://i.stack.imgur.com/LY5OD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LY5OD.png" alt="enter image description here"></a>

blocks|key|3153622|text|除了前面的答案之外，根据您要检查的阵列架构，请执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3153623|function+is_multi_array($array=[],$mode='every_key'){

++++$result+=+false;

++++if(is_array($array)){

++++++++if($mode=='first_key_only'){

++++++++++++if(is_array(array_shift($array))){

++++++++++++++++$result+=+true;
++++++++++++}
++++++++}
++++++++elseif($mode=='every_key'){

++++++++++++$result+=+true;

++++++++++++foreach($array+as+$key+=>+$value){

++++++++++++++++if(!is_array($value)){

++++++++++++++++++++$result+=+false;
++++++++++++++++++++break;
++++++++++++++++}
++++++++++++}
++++++++}
++++++++elseif($mode=='at_least_one_key'){

++++++++++++if(count($array)!==count($array,+COUNT_RECURSIVE)){

++++++++++++++++$result+=+true;+
++++++++++++}
++++++++}
++++}

++++return+$result;
}|code-block|syntax|javascript|3153624|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In addition to the previous answers and depending on the schema of the array you want to check:

<pre><code>function is_multi_array($array=[],$mode='every_key'){

 $result = false;

 if(is_array($array)){

 if($mode=='first_key_only'){

 if(is_array(array_shift($array))){

 $result = true;
 }
 }
 elseif($mode=='every_key'){

 $result = true;

 foreach($array as $key =&gt; $value){

 if(!is_array($value)){

 $result = false;
 break;
 }
 }
 }
 elseif($mode=='at_least_one_key'){

 if(count($array)!==count($array, COUNT_RECURSIVE)){

 $result = true; 
 }
 }
 }

 return $result;
}
</code></pre>

blocks|key|361013|text|请按如下方式尝试|type|unstyled|depth|inlineStyleRanges|entityRanges|data|361014|if+(count($arrayList)+!=+count($arrayList,+COUNT_RECURSIVE))+
{
++echo+'arrayList+is+multidimensional';

}else{

++echo+'arrayList+is+no+multidimensional';
}|code-block|syntax|javascript|361015|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Try as follows 

<pre><code>if (count($arrayList) != count($arrayList, COUNT_RECURSIVE)) 
{
 echo 'arrayList is multidimensional';

}else{

 echo 'arrayList is no multidimensional';
}
</code></pre>

blocks|key|3366564|text|我认为这是最直接的方式，也是最先进的方式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3366565|function+is_multidimensional(array+$array)+{
++++return+count($array)+!==+count($array,+COUNT_RECURSIVE);
}|code-block|syntax|javascript|3366566|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I think this is the most straight forward way and it's state-of-the-art:

<pre><code>function is_multidimensional(array $array) {
 return count($array) !== count($array, COUNT_RECURSIVE);
}
</code></pre>

blocks|key|363003|text|即使这样也行得通|type|unstyled|depth|inlineStyleRanges|entityRanges|data|363004|is_array(current($array));|code-block|syntax|javascript|363005|If+false它是一维数组if+true它是多维数组。|offset|length|style|BOLD|363006|current将提供数组的第一个元素，并通过is_array函数检查第一个元素是否为数组。|363007|entityMap^0|0|0|3|5|A|2|H|4|N|2|0|0|7|M|8|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]|$I|V|J|W|K|L]|$I|X|J|Y|K|L]|$I|Z|J|10|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|11|8|@$I|12|J|13|K|L]|$I|14|J|15|K|L]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|16|8|@]|9|@]|A|$]]]|P|$]]

Even this works

<pre><code>is_array(current($array));
</code></pre>

If false its a single dimension array if true its a multi dimension array.

current will give you the first element of your array and check if the first element is an array or not by is_array function.

blocks|key|3153720|text|不要使用COUNT_RECURSIVE|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3153721|click+this+site+for+know+why|offset|length|3153722|使用rsort，然后使用isset|3153723|function+is_multi_array(+$arr+)+{
rsort(+$arr+);
return+isset(+$arr[0]+)+&&+is_array(+$arr[0]+);
}
//Usage
var_dump(+is_multi_array(+$some_array+)+);|code-block|syntax|javascript|3153724|entityMap|0|LINK|mutability|MUTABLE|url|https://pageconfig.com/post/checking-multidimensional-arrays-in-php^0|0|0|S|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@$D|W|E|X|1|Y]]|A|$]]|$1|F|3|G|5|6|7|Z|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|10|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

Don't use COUNT_RECURSIVE

<a href="https://pageconfig.com/post/checking-multidimensional-arrays-in-php" rel="nofollow noreferrer">click this site for know why</a>

use rsort and then use isset

<pre><code>function is_multi_array( $arr ) {
rsort( $arr );
return isset( $arr[0] ) &amp;&amp; is_array( $arr[0] );
}
//Usage
var_dump( is_multi_array( $some_array ) );
</code></pre>

blocks|key|363035|text|就我的情况而言。我陷入了各种奇怪的境地。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|363036|第一种情况=+array("data"=>+"name");|offset|length|style|CODE|363037|第二种情况=+array("data"=>+array("name"=>"username","fname"=>"fname"));|363038|但是如果data使用数组而不是值，那么sizeof()或count()函数不适用于这种情况。然后创建自定义函数进行检查。|363039|如果数组第一个索引有值，则返回“唯一值”|363040|但是如果索引包含数组而不是值，则返回"has+array“|363041|我是这样用的|363042|+function+is_multi($a)+{
++++++++foreach+($a+as+$v)+{
++++++++++if+(is_array($v))+
++++++++++{
++++++++++++return+"has+array";
++++++++++++break;
++++++++++}
++++++++++break;
++++++++}
++++++++return+'only+value';
++++}|code-block|syntax|javascript|363043|特别感谢Vinko+Vrsalovic|363044|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/145337/checking-if-array-is-multidimensional-or-not/145348#145348^0|0|7|N|0|7|1N|0|4|4|0|0|0|0|0|4|F|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|17|8|@$D|18|E|19|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|1A|8|@$D|1B|E|1C|F|G]]|9|@]|A|$]]|$1|J|3|K|5|6|7|1D|8|@$D|1E|E|1F|F|G]]|9|@]|A|$]]|$1|L|3|M|5|6|7|1G|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|1H|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1I|8|@]|9|@]|A|$]]|$1|R|3|S|5|T|7|1J|8|@]|9|@]|A|$U|V]]|$1|W|3|X|5|6|7|1K|8|@]|9|@$D|1L|E|1M|1|1N]]|A|$]]|$1|Y|3|-4|5|6|7|1O|8|@]|9|@]|A|$]]]|Z|$10|$5|11|12|13|A|$14|15]]]]

In my case. I stuck in vary strange condition. 
1st case = <code>array("data"=&gt; "name");</code> 
2nd case = <code>array("data"=&gt; array("name"=&gt;"username","fname"=&gt;"fname"));</code> 
But if <code>data</code> has array instead of value then sizeof() or count() function not work for this condition. Then i create custom function to check.
 
If first index of array have value then it return "only value" 
But if index have array instead of value then it return "has array" 
I use this way

<pre><code> function is_multi($a) {
 foreach ($a as $v) {
 if (is_array($v)) 
 {
 return "has array";
 break;
 }
 break;
 }
 return 'only value';
 }
</code></pre>

Special thanks to <a href="https://stackoverflow.com/questions/145337/checking-if-array-is-multidimensional-or-not/145348#145348">Vinko Vrsalovic</a>

blocks|key|363051|text|本机print_r函数返回人类可读的字符串。只需计算"Array“实例数即可。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|363052|试试..。|363053|substr_count(print_r([...array...],+true),+'Array')+>+1;

$a+=+array(1+=>+'a',2+=>+'b',3+=>+array(1,2,3));
$b+=+array(1+=>+'a',2+=>+'b');
$c+=+array(1+=>+'a',2+=>+'b','foo'+=>+array(1,array(2)));
$d+=+array(array());
$e+=+array(1,+array());
$f+=+array(array(),+array());
$g+=+array("hello",+"hi"+=>+"hi+there");
$h[]+=+$g;

var_dump(substr_count(print_r($a,+true),+'Array')+>+1);
...

//a:+bool(true)
//b:+bool(false)
//c:+bool(true)
//d:+bool(true)
//e:+bool(true)
//f:+bool(true)
//g:+bool(false)
//h:+bool(true)|code-block|syntax|javascript|363054|在我的盒子里，"is_multi在500000次中花了0.83681297302246秒“|363055|礼节:+Ruach+HaKodesh|363056|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

The native print_r function returns a human-readable string. Just count the "Array" instances.

try...

<pre><code>substr_count(print_r([...array...], true), 'Array') &gt; 1;

$a = array(1 =&gt; 'a',2 =&gt; 'b',3 =&gt; array(1,2,3));
$b = array(1 =&gt; 'a',2 =&gt; 'b');
$c = array(1 =&gt; 'a',2 =&gt; 'b','foo' =&gt; array(1,array(2)));
$d = array(array());
$e = array(1, array());
$f = array(array(), array());
$g = array("hello", "hi" =&gt; "hi there");
$h[] = $g;

var_dump(substr_count(print_r($a, true), 'Array') &gt; 1);
...

//a: bool(true)
//b: bool(false)
//c: bool(true)
//d: bool(true)
//e: bool(true)
//f: bool(true)
//g: bool(false)
//h: bool(true)
</code></pre>

On my box, "is_multi took 0.83681297302246 seconds in 500000 times"

Courtesy: Ruach HaKodesh

blocks|key|3366686|text|它就像这样简单|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3366687|$isMulti+=+!empty(array_filter($array,+function($e)+{
++++++++++++++++++++return+is_array($e);
++++++++++++++++}));|code-block|syntax|javascript|3366688|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Its as simple as 

<pre><code>$isMulti = !empty(array_filter($array, function($e) {
 return is_array($e);
 }));
</code></pre>

blocks|key|3153776|text|$is_multi_array+=+array_reduce(array_keys($arr),+function+($carry,+$key)+use+($arr)+{+return+$carry+&&+is_array($arr[$key]);+},+true);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3153777|这里有一个很好的眼线。它遍历每个键以检查该键的值是否为数组。这将确保真实的|unstyled|3153778|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>$is_multi_array = array_reduce(array_keys($arr), function ($carry, $key) use ($arr) { return $carry &amp;&amp; is_array($arr[$key]); }, true);
</code></pre>

Here is a nice one liner. It iterates over every key to check if the value at that key is an array. This will ensure true

blocks|key|3366706|text|在PHP+7之后，您可以简单地执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3366707|public+function+is_multi(array+$array):bool
{
++++return+is_array($array[array_key_first($array)]);
}|code-block|syntax|javascript|3366708|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

After PHP 7 you could simply do:
<pre><code>public function is_multi(array $array):bool
{
 return is_array($array[array_key_first($array)]);
}
</code></pre>

<ol>
<li>What is the most efficient way to check if an array is a flat array
of primitive values or if it is a multidimensional array?</li>
<li>Is there any way to do this without actually looping through an
array and running <code>is_array()</code> on each of its elements?</li>
</ol>

Checking if array is multidimensional or not?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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检查一个数组是否是由原始值组成的平面数组的最有效方法是还是多维arrayIs有什么方法可以做到这一点，而不是实际循环一个数组并对它的每个元素运行？

问检查数组是否为多维？
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问检查数组是否为多维？EN